Bystander Says Good Samaritan Was Right to Shoot Trooper's Assailant

— -- A Scottsdale, Arizona former medic who helped a trooper ambushed during a traffic stop said a Good Samaritan who shot and killed the officer's assailant "did what we had to do."

A dramatic scene unfolded during the confrontation when the Good Samaritan told the assailant to stop assaulting the officer and then shot and killed the attacker, according to police.

The Department of Public Safety today identified the officer as 27-year veteran state Trooper Ed Andersson.

The medic, Brian Schober, is the man heard calling for help on the trooper's radio, saying "Officer down. ... Officer down."

"I am glad that he was there and did what he did," Schober said about the Good Samaritan.

Good Samaritan Motorist Kills Man Who Shot, Assaulted State Trooper

According to the Department of Public Safety, the incident started around 4 a.m. when Andersson responded to a call about gunfire in the area.

Department Director Ralph Milstead said the driver had called police to report being shot at while driving along Interstate 10.

As the trooper arrived in the general vicinity where the caller had reported being shot at, the trooper spotted a rollover car wreck, where a woman had been ejected. She was later pronounced dead at the hospital.

It was unclear if the person who fired at the vehicle is the suspect who shot the trooper.

As Andersson was blocking off lanes and setting up flares, the assailant shot the trooper in the chest and then proceeded to physically attack him, Milstead said. Police said they believe that the man who shot and assaulted the trooper was the driver of the vehicle that crashed.

A Good Samaritan who noticed the altercation pulled over and asked the officer whether he needed help, to which he said yes. According to authorities today, the Good Samaritan's fiance also called 911. The motorist then retrieved a gun from his car and fatally shot the suspect.

Authorities said today that Andersson underwent surgery Thursday and was doing well. They also said the motorist who shot the suspect did not want to be interviewed by the media.

"My trooper would not be alive without his assistance," Milstead said of the motorist.

Schober told ABC News recently that he knew right away something was wrong when he saw the trooper's car on the side of the highway and said the Good Samaritan had waved him over.

"I got out of my car and assessed the situation," he said.

He said the Good Samaritan's fiance helped him administer first aid to the officer. He said he also called for help using the trooper's radio.

"I didn't know what was going to happen," he said. "We did what we had to do. ... God put us at the right place at the right time."

Schober said there was no doubt the Good Samaritan saved the trooper's life. According to Schober, the suspect was bashing the trooper's head into the concrete, leaving him with severe cuts on the back and side of his head.

Officials had not yet confirmed the suspect's identity or the deceased occupant of the vehicle, Milstead added.